org.apache.activemq.filter.function
Class regexMatchFunction

java.lang.Object
  org.apache.activemq.filter.function.regexMatchFunction

All Implemented Interfaces:

FilterFunction

public class regexMatchFunction
extends Object
implements FilterFunction

Filter function that matches a value against a regular expression.

REGEX( 'A.B', 'A-B' )

Note that the regular expression is not anchored; use the anchor characters, ^ and $, as-needed. For example, REGEX( 'AA', 'XAAX' ) evaluates to true while REGEX( '^AA$' , 'XAAX' ) evaluates to false.

Field Summary

protected static LRUCache<String,Pattern>

compiledExprCache

Constructor Summary

regexMatchFunction()

Method Summary

Object	evaluate(FunctionCallExpression expr, MessageEvaluationContext message) Evalutate the given expression, which consists of a call to this function, in the context given.
protected Pattern	getCompiledPattern(String reg_ex_str) Retrieve a compiled pattern for the given pattern string.
boolean	isValid(FunctionCallExpression expr) Check whether the given expression is a valid call of this function.
boolean	returnsBoolean(FunctionCallExpression expr) Indicate that this Filter Function evaluates to a Boolean result.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

compiledExprCache

protected static final LRUCache<String,Pattern> compiledExprCache

Constructor Detail

regexMatchFunction

public regexMatchFunction()

Method Detail

isValid

public boolean isValid(FunctionCallExpression expr)

Check whether the given expression is a valid call of this function. Two arguments are required. When evaluated, the arguments are converted to strings if they are not already strings.

Specified by:

isValid in interface FilterFunction

Parameters:

expr - - the expression consisting of a call to this function.

Returns:

true - if the expression is valid; false - otherwise.

returnsBoolean

public boolean returnsBoolean(FunctionCallExpression expr)

Indicate that this Filter Function evaluates to a Boolean result.

Specified by:

returnsBoolean in interface FilterFunction

Parameters:

expr - - the expression consisting of a call to this function.

Returns:

true - this function always evaluates to a Boolean result.

evaluate

public Object evaluate(FunctionCallExpression expr,
                       MessageEvaluationContext message)
                throws javax.jms.JMSException

Evalutate the given expression, which consists of a call to this function, in the context given. Returns an indication of whether the second argument matches the regular expression in the first argument.

Specified by:

evaluate in interface FilterFunction

Parameters:

expr - - the expression consisting of a call to this function.

message_ctx - - the context in which the call is being evaluated.

Returns:

true - if the value matches the regular expression; false - otherwise.

Throws:

javax.jms.JMSException

getCompiledPattern

protected Pattern getCompiledPattern(String reg_ex_str)

Retrieve a compiled pattern for the given pattern string. A cache of recently used strings is maintained to improve performance.

Parameters:

reg_ex_str - - the string specifying the regular expression.

Returns:

Pattern - compiled form of the regular expression.